JaMarcus Russell debut on Sunday?

No. 1 overall draft pick JaMarcus Russell could make his NFL debut Sunday, not by climbing the depth chart so much as climbing over a pile of injured quarterbacks.

Raiders quarterback Daunte Culpepper was limited in practice Thursday by a thigh injury. He said it was precautionary move, and there’s no telling yet if he’ll be able to start Sunday against the visiting Broncos.

His backup, former starter Josh McCown, showed up on the locker room with his left hand wrapped in ice. He dislocated two joints in his left pinkie during practice Wednesday.

If Culpepper and McCown can’t go, Russell would be next in line for starting duty, though Andrew Walter remains an outside possibility. Raiders coach Lane Kiffin declined to speculate, saying the Raiders have one more day of practice to see how everyone feels.

In the least, Russell could move into the No. 2 position — the next step in his progression toward playing, Kiffin has said.

If Russell does play Sunday, it will be in front a full house at The Coliseum. Team officials confirmed the game has sold out and will be televised locally.

Speaking of McCown, he had a hilarious exchange with quarterback Andrew Walter in the locker room. McCown’s hand was hurt catching a Walter pass during practice Wednesday.

McCown: “I wouldn’t have got hurt if it was a spiral.”

Walter: “That was the best pass I’ve thrown all year.”

McCown: “It probably was.”

McCown then proceeded with a conspiracy theory, jokingly accusing Walter of trying to take out the quarterbacks ahead of him on the depth chart.

He compared Walter’s throw to the magic bullet of JFK conspiracy fame.

“Off Daunte’s quad, off my pinkie, right into JaMarcus’ eye,” McCown said. “That was the plan.”

Good to know two former starters can still enjoy life in a tough situation.